Broadly speaking, I have to agree that warrior women should be the exception not the rule.
On the other hand, the sketchiness of female characters
does allow for wonderful interpretation and fanfiction: see
this story, In Brethil's Shade, focussing on Haleth.
But more to the point-while Faramira and Imrahila are rather ludicrous ideas if they are to appear on the field of battle, and a female fellowship member is aesthetically ugly, there is a simple solution.
Explore the world outside the battlefield. Let's play
Agamemnon, not
Iliad. Let's see Pippin's sisters amidst the Scouring, let's see Arwen and her trusted handmaids talking at Rivendell; let's see Galadriel and her seamstresses at work. This will call for a more
War and Peace-like balance of course...
...and Tolkien isn't Tolstoy. So alas we cannot envisage it from his own pen. But that leaves all the more for us!
That's why, in my opinion, fanfiction writers and role-players are vitally important elements of the...study...of Tolkien, particularly when we stray from the beaten path; to the East, into peace and prosperity, and/or in my lady's chamber. The uncanonical writers dabble their fingers in mercury, split the atom, serve on the front line and conduct the cavalry charge.